1. Field of the Invention
The present invention relates to electronic phase shifters, but more specifically it relates to an electronic phase shifter wherein a sine wave can be phase shifted without affecting the magnitude thereof over a wide input magnitude range as measured at the output of the electronic phase shifter.
2. Description of the Prior Art
The phase shifting of sine wave type signals is accomplished in many different ways depending on system requirements. For example, there are networks having mechanical adjusters which shift the phase of one voltage with respect to another voltage of the same frequency; there are devices which produce, from a single input waveform, two or more output waveforms that differ in phase from one another; and, there are devices in which the output voltage (or current) may be adjusted to have some desired phase relationship with the input voltage (or current). Respectively, each of the foregoing has had operational deficiencies such as use limited to low frequency applications because of the inability of the arrangement to respond to the more rapid phase shifting rates required with the higher frequencies; the phase difference between the two or more output waveforms varying substantially with frequency so that practical use with a reasonable frequency range is limited; and, the amplitude of phase shifted output voltage (or current) varying substantially with frequency, and/or the phase shift is fixed at, say, -90.degree..
The foregoing operational deficiencies have to a large degree been eliminated, but usually with the added disadvantages of increased costs, limited signal voltage range, increased circuit complexity, unpredictability of unit-to-unit performance and decreased reliability. Consequently, there is a need in the prior art to configure an electronic phase shifter capable of substantially 180.degree. phase shift over a wide frequency range but yet having an output magnitude unaffected by the phase shifting operation while eliminating the foregoing disadvantages.
The prior art, as indicated hereinabove, include advances in phase shifters, including eliminating changes in the amplitude of the output waveform with changes in phase shifting. However, insofar as can be determined, no prior art phase shifter incorporates all of the features and advantages of the present invention.